Ion-selective solid-state polymeric membrane electrondes

Abstract

An improved ion-sensing electrode for detecting ions or polyions is provided having an electrically conducting member sheathed or coated with a layer of insulation except at an exposed, uninsulated area, where the insulation free surface of the electrically conducting member is texturized, and a polymeric membrane coated on the insulation-free surface of the electrically conducting member, where the ion selective membrane includes an ionophore. The texturized surface improves the starting EMF stability and reproducibility of the ion-sensing electrodes, and further improves membrane adherence to the electrically conducting member.

1 - 68 . (canceled)  
     
     
         69 . An ion-sensing electrode comprising: 
 an electrically conductive member having a textured surface; and    an ion-selective polymer membrane that completely coats and is in direct contact with the textured surface of said electrically conductive member, said membrane comprising an ionophore responsive to protamine or heparin.    
     
     
         70 . The ion-sensing electrode of  claim 69  further comprising a layer of electrical insulation surrounding said electrically conductive member, wherein the textured surface of said electrically conductive member is uninsulated.  
     
     
         71 . The ion-sensing electrode of  claim 69  wherein said electrically conductive member is selected from the group consisting of silver, copper, platinum, gold, palladium, iridium, aluminum, nickel, stainless steel, iron, and an electrically conductive metal deposited onto a portion of a non-conductive substrate.  
     
     
         72 . The ion-sensing electrode of  claim 69  wherein said ion-selective polymer membrane further comprises a polymeric matrix material and a plasticizer.  
     
     
         73 . The ion-sensing electrode of  claim 69  wherein said ionophore responsive to protamine is a negatively charged lipophilic anion.  
     
     
         74 . The ion-sensing electrode of  claim 73  wherein the negatively charged lipophilic anion is derived from a salt of an organosulfonate, organoborate, organophosphate or organophosphonate.  
     
     
         75 . The ion-sensing electrode of  claim 74  wherein said salt of a sulfonate is dinonylnaphthalene sulfonate, didodecylnaphthalene sulfonate, or dihexadecylnaphthalene sulfonate.  
     
     
         76 . The ion-sensing electrode of  claim 74  wherein said salt of an organoborate is a salt of a tetraphenylborate selected from the group consisting of sodium tetraphenylborate, potassium tetrakis(4-chlorophenyl) borate, tetraphenylammoniumtetraphenyl borate, sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, and potassium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate.  
     
     
         77 . The ion-sensing electrode of  claim 76  wherein the salt of a tetraphenylborate is potassium tetrakis(4-chlorophenyl) borate.  
     
     
         78 . The ion-sensing electrode of  claim 74  wherein said salt of an organophosphate or organophosphonate is selected from the group consisting of calcium bis[4-(1,1,3,3,-tetramethylbutyl)phenyl] phosphate, dioctylphenyl phosphonate, and tris(2-ethylhexyl) phosphate.  
     
     
         79 . The ion-sensing electrode of  claim 78  wherein said salt of an organophosphate is calcium bis[4-(1,1,3,3,-tetramethylbutyl)phenyl] phosphate.  
     
     
         80 . The ion-sensing electrode of  claim 69  wherein said ionophore responsive to heparin is selected from the group consisting of quaternary ammonium salts, quaternary phosphonium salts, and quaternary arsonium salts.  
     
     
         81 . The ion-sensing electrode of  claim 80  wherein said ionophore is a quaternary ammonium salt.  
     
     
         82 . The ion-sensing electrode of  claim 80  wherein said quaternary ammonium salt is selected from the group consisting of triethylphenylammonium iodide, tetrapentylammonium bromide, trimethylphenylammonium chloride, dimethyldioctadecylammonium bromide, tetraoctylammonium bromide, hexadecyltrimethylammonium bromide, tetraethylammonium perchlorate, tetramethylammonium bromide, tetrabutylammonium iodide, tridodecylmethylammonium chloride, polybrene, and trioctylmethylammoniumchloride  
     
     
         83 . The ion-sensing electrode of  claim 82  wherein said quaternary ammonium salt is tridodecylmethylammonium chloride.  
     
     
         84 . The ion-sensing electrode of  claim 72  wherein said polymer matrix material is a film-forming, hydrophobic polymer or copolymer.  
     
     
         85 . The ion-sensing electrode of  claim 84  wherein said polymeric matrix material is selected from the group consisting of poly(vinyl chloride), polyurethane, cellulose triacetate, poly(vinyl alcohol)/poly(vinyl chloride) copolymer, and silicone rubber.  
     
     
         86 . The ion-sensing electrode of  claim 85  wherein said polymeric matrix material is poly(vinyl chloride).  
     
     
         87 . The ion-sensing electrode of  claim 72  wherein said plasticizer is one or more plasticizers selected from the group consisting of 2-nitrophenyl octyl ether, dioctyl phthalate, dioctyl sebacate, dioctyl adipate, dibutyl sebacate, dibutyl phthalate, 1-decanol, 5-phenyl-1-pentanol, tetraundecyl benzhydrol 3,3′,4,4′ tetracarboxylate, benzyl ether, dioctylphenyl phosphonate, tris(2-ethylhexyl) phosphate, and fluorophenyl nitrophenyl ether.  
     
     
         88 . The ion-sensing electrode of  claim 87  wherein said plasticizer is 2-nitrophenyloctyl ether.  
     
     
         89 . The ion-sensing electrode of  claim 87  wherein said plasticizer is tris(2-ethylhexyl) phosphate.  
     
     
         90 . The ion-sensing electrode of  claim 72  wherein said ion-selective polymer membrane comprises, in admixture, about 0.1 to 5 percent by weight of said ionophore selective for protamine or said ionophore selective for heparin, about 30 to 70 percent by weight of said plasticizer, and about 30 to 70 percent by weight of said polymer matrix material.  
     
     
         91 . A method for producing an ion-sensing electrode having a structurally strong ion selective membrane, said method comprising: 
 a) forming an electrically conductive member electrically insulated with a layer of electrical insulation, said conductive member having an uninsulated surface;    b) texturizing said uninsulated surface of said conductive member;    c) preparing a liquid solution comprising a polymeric membrane formulation comprising an ionophore responsive to protamine or heparin and a solvent;    d) coating the texturized surface of said conductive member with said liquid solution so that the liquid solution is in direct contact with said texturized surface; and    e) evaporating the solvent to form an ion selective membrane that is in direct contact with, and adheres to, said conductive member, thereby forming an ion-sensing electrode having a structurally strong ion selective membrane.    
     
     
         92 . The method of  claim 91  wherein said electrically conductive member is selected from the group consisting of silver, copper, platinum, gold, palladium, iridium, aluminum, nickel, stainless steel, iron, and mixtures thereof.  
     
     
         93 . The method of  claim 91  wherein said insulated electrically conductive member is an insulated wire and said uninsulated surface is formed by cutting said insulation away from one surface of said wire.  
     
     
         94 . The method of  claim 91  wherein said uninsulated surface is texturized by beadblasting said uninsulated surface.  
     
     
         95 . The method of  claim 91  wherein said electrically conductive member comprises an electrically conductive metal deposited onto a portion of a non-conductive substrate.  
     
     
         96 . The method of  claim 91  wherein said layer of electrical insulation is comprised of a material selected from the group consisting of poly(vinyl chloride), copolymers of poly(vinyl chloride), polymers compatible with polyvinyl chloride, polyethylene, polypropylene, nylon, and silicone rubber.  
     
     
         97 . The method of  claim 91  wherein said polymer membrane formulation further comprises a polymer matrix material and a plasticizer.  
     
     
         98 . The method of  claim 91  wherein said ionophore responsive to protamine is a negatively charged lipophilic anion.  
     
     
         99 . The method of  claim 98  wherein the negatively charged lipophilic anion is derived from a salt of a sulfonate, organoborate, organophosphate or organophosphonate.  
     
     
         100 . The method of  claim 99  wherein said salt of a sulfonate is dinonylnaphthalene sulfonate, didodecylnaphthalene sulfonate, or dihexadecylnaphthalene sulfonate.  
     
     
         101 . The method of  claim 99  wherein said salt of an organoborate is a salt of a tetraphenylborate selected from the group consisting of sodium tetraphenylborate, potassium tetrakis(4-chlorophenyl) borate, tetraphenylammonium tetraphenyl borate, sodium tetrakis[3,5-bis-(trifluoromethyl)phenyl]borate, and potassium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate.  
     
     
         102 . The method of  claim 101  wherein the salt of a tetraphenylborate is potassium tetrakis(4-chlorophenyl) borate.  
     
     
         103 . The method of  claim 99  wherein said salt of an organophosphate or organophosphonate is selected from the group consisting of calcium bis[4-(1,1,3,3,-tetramethylbutyl)phenyl] phosphate, dioctylphenyl phosphonate, and tris(2-ethylhexyl) phosphate.  
     
     
         104 . The method of  claim 103  wherein said salt of an organophosphate is calcium bis[4-(1,1,3,3,-tetramethylbutyl)phenyl] phosphate.  
     
     
         105 . The method of  claim 91  wherein said ionophore responsive to heparin is selected from the group consisting of quaternary ammonium salts, quaternary phosphonium salts, and quaternary arsonium salts.  
     
     
         106 . The method of  claim 105  wherein said ionophore is a quaternary ammonium salt.  
     
     
         107 . The method of  claim 105  wherein said quaternary ammonium salt is selected from the group consisting of triethylphenylammonium iodide, tetrapentylammonium bromide, trimethylphenylammonium chloride, dimethyldioctadecylammonium bromide, tetraoctylammonium bromide, hexadecyltrimethylammonium bromide, tetraethylammonium perchlorate, tetramethylammonium bromide, tetrabutylammonium iodide, tridodecylmethylammonium chloride, polybrene, and trioctylmethylammoniumchloride.  
     
     
         108 . The method of  claim 107  wherein said quaternary ammonium salt is tridodecyl methyl ammonium chloride.  
     
     
         109 . The method of  claim 91  wherein said polymer matrix material is a film-forming, hydrophobic polymer or copolymer.  
     
     
         110 . The method of  claim 109  wherein said polymeric matrix material is selected from the group consisting of poly(vinyl chloride), polyurethane, cellulose triacetate, poly(vinyl alcohol)/poly(vinyl chloride) copolymer, and silicone rubber.  
     
     
         111 . The method of  claim 110  wherein said polymeric matrix material is poly(vinyl chloride).  
     
     
         112 . The method of  claim 97  wherein said plasticizer is one or more plasticizers selected from the group consisting of 2-nitrophenyloctyl ether, dioctyl phthalate, dioctyl sebacate, dioctyl adipate, dibutyl sebacate, dibutyl phthalate, 1-decanol, 5-phenyl-1-pentanol, tetraundecyl benzhydrol 3,3′,4,4′ tetracarboxylate, benzyl ether, dioctylphenyl phosphonate, tris(2-ethylhexyl) phosphate, and fluorophenyl nitrophenyl ether.  
     
     
         113 . The method of claim  1   12  wherein said plasticizer is 2-nitrophenyl octyl ether.  
     
     
         114 . The method of  claim 112  wherein said plasticizer is tris(2-ethylhexyl) phosphate.  
     
     
         115 . The method of  claim 97  wherein said ion-selective polymer membrane comprises, in admixture, about 0.1 to 5 percent by weight of said ionophore selective for protamine or said ionophore selective for heparin, about 30 to 70 percent by weight of said plasticizer, and about 30 to 70 percent by weight of said polymer matrix material.  
     
     
         116 . A method for producing an ion-sensing electrode having a structurally strong ion selective membrane, said method comprising: 
 a) forming an electrically conductive member electrically insulated with a layer of electrical insulation, said conductive member having an uninsulated surface;    b) texturizing said uninsulated surface of said conductive member;    c) preparing a liquid solution comprising a polymeric membrane formulation comprising a solvent and a negatively charged lipophilic anion responsive to protamine, said anion selected from the group consisting of dinonylnaphthalene sulfonate, didodecylnaphthalene sulfonate, and dihexadecylnaphthalene sulfonate;    d) coating the texturized surface of said conductive member with said liquid solution so that the liquid solution is in direct contact with said texturized surface; and    e) evaporating the solvent to form an ion selective membrane that is in direct contact with, and adheres to, said conductive member, thereby forming an ion-sensing electrode having a structurally strong ion selective membrane.